/*
* Copyright (c) 2009, Roc King
* All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
*     * Redistributions of source code must retain the above copyright
*       notice, this list of conditions and the following disclaimer.
*     * Redistributions in binary form must reproduce the above copyright
*       notice, this list of conditions and the following disclaimer in the
*       documentation and/or other materials provided with the distribution.
*     * Neither the name of the OwnWaterloo,Roc King nor the
*       names of its contributors may be used to endorse or promote products
*       derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <assert.h>
#include <stdlib.h>
#include "student.h"

template<course_category category>
int compare(const void* student1,const void* student2) {
    int mark1 = static_cast<const student*>(student1)->mark[category];
    int mark2 = static_cast<const student*>(student2)->mark[category];
    return mark1 - mark2;
}

void sort_by_course(student students[],size_t count,course_category category) {
    typedef int ( * qsort_comparison)(const void*,const void*);
    static const qsort_comparison comparisons[] = {
        compare<chinese>,       // IMPLEMENT_COMPARISON here
        compare<mathematics>,
        compare<english>,
        /*
        compare<physics>,
        compare<chemistry>,
        compare<biology>,
        */
    };

    if (category<0 || category>=course_category_end) {
        assert(0 && "invalid course category");
        return ;
    }
    qsort(students,count,sizeof(student),comparisons[category]);
}
